Hierarchical closed-loop flow control system for aircraft, missiles and munitions

ABSTRACT

The present invention relates to a missile or aircraft with a hierarchical, modular, closed-loop flow control system and more particularly to aircraft or missile with a flow control system for enhanced aerodynamic control, maneuverability and stabilization and methods of operating the flow control system. Various embodiments of the flow control system of the present invention involve flow sensors, active flow control device or activatable flow effectors and/or logic devices with closed loop control architecture. The sensors are used to estimate or determine flow conditions on surfaces of a missile or aircraft. The active flow control device or activatable flow effectors of these various embodiments create on-demand flow disturbances, preferably micro-disturbances, at different points along various aerodynamic surfaces of the missile or aircraft to achieve a desired stabilization or maneuverability effect. The logic devices are embedded with a hierarchical control structure allowing for rapid, real-time control at the flow surface.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/010,909, filed on Aug. 27, 2013, now U.S. Pat. No. 9,310,166, whichwas a continuation of U.S. patent application Ser. No. 13/455,182, filedon Apr. 25, 2012, and which issued as U.S. Pat. No. 8,548,650 on Oct. 1,2013, which was a continuation of U.S. patent application Ser. No.12/557,599, filed on Sep. 11, 2009, and which issued as U.S. Pat. No.8,190,305 on May 29, 2012, which was a continuation of U.S. patentapplication Ser. No. 11/311,767, filed on Dec. 19, 2005, now abandoned,which was a continuation of U.S. patent application Ser. No. 10/725,266filed on Dec. 1, 2003, and which issued as U.S. Pat. No. 8,417,395 onApr. 9, 2013, and which was a continuation-in-part of U.S. patentapplication Ser. No. 10/336,117 filed Jan. 3, 2003, which issued as U.S.Pat. No. 6,685,143 on Feb. 3, 2004.

The U.S. Government has a paid-up license in this invention and theright in limited circumstances to require the patent owner to licenseothers on reasonable terms provided for by the terms of grant numberF33615-02-M-32217 awarded by the United States Air Force.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a missile or aircraft with ahierarchical closed-loop flow control system and more particularly toaircraft or missile with a flow control system for aerodynamic control,maneuverability and stabilization. The present invention further relatesto a method of operating the flow control system.

2. Technical Background

Traditional aircraft and missile maneuvering technologies utilize hingedcontrol surfaces such as the wings, tail-fins and forebody-canards toprovide control and stability through all phases of an aircraft's ormissile's flight path. These control surfaces require significant volumeto house the control actuation system, which includes heavy servomotors,thereby imposing significant limitations on the aircraft or missile'saerodynamic performance. These hinged-control surfaces also reduce theeffective payload, maximum achievable range, and lethality of missilesand aircraft.

Conventional missile and aircraft control techniques are not capable ofmeeting new multi-mission highly accurate, long-range fire requirementsthat are needed to ensure the multi-target engagement capabilities ofmissiles or aircraft, particularly “smart” missiles and aircraft. Inaddition, with a missile the overall cost of the control system perround needs to be minimum without affecting the aerodynamic efficiencyof the missiles considering their subsistence period once deployed. Themajor disadvantages of traditional control surfaces is spacerestriction, i.e., control surfaces must be located in an annular spacearound the throat of the propulsion nozzle; increased weight; and dragfrom exposed surfaces. The conventional control surfaces necessitatehinges, which increase the overall weight induced aerodynamic drag andalso the complexity of the propulsion system. There is therefore a needfor a distributed control system for improving performance of aircraft,missiles and munitions.

Active flow control enables a mechanism to alter the flow around theaerodynamic surface(s) in order to achieve a desired air vehiclemaneuver by utilizing micro-actuators that are located optimally on theaerodynamic surface of air vehicles. Most of the active flow controlsystems currently in use, or under investigation, operate in theopen-loop mode, i.e., the control input (via micro-actuators) is notcontinuously adjusted based on the sensor information. Such open-loopflow control systems fail to maintain the required aerodynamicperformance of the air vehicle under dynamic conditions. Dynamic, inthis context, is referred to flow instabilities or vehicle motion. Inview of the foregoing disadvantages of currently used control surfacesand open-loop flow control systems, it has become desirable to develop arobust, closed-loop, active flow control system that provides thenecessary control moments in real-time by utilizing fast-responsesensors and fast-acting control actuators, so as to maintain and enhancethe overall aerodynamic performance of the missile or the aircraft. Itis further desirable to develop a flow control system for missile andaircraft control that enables low-cost, low-weight and low-volumesensor-actuator-controller modules to control local flow phenomena forenhanced aerodynamic performance. It is still even further desirable todevelop a missile, aircraft and munition control system that can controlnumerous flow control devices with associated sensors using amulti-tiered, hierarchical control architecture using a higher levelcontroller for real-time aerodynamic control.

SUMMARY OF THE INVENTION

The present invention relates to a missile or aircraft with ahierarchical, closed-loop flow control system and more particularly toaircraft or missile with a flow control system for enhanced aerodynamiccontrol, maneuverability and stabilization. The present inventionfurther relates to a method of operating the flow control system.

Various embodiments of the flow control system of the present inventioninvolve different elements including flow sensors; active flow controldevices or activatable flow effectors; and logic devices with closedloop control architecture. The sensors of these various embodiments areused to estimate or determine typical flow conditions, such as flowseparation, on various surfaces of a missile or aircraft. The activeflow control devices or activatable flow effectors of these variousembodiments create on-demand flow disturbances, preferablymicro-disturbances, to affect the flowfield in a desired manner atdifferent points along the various aerodynamic surfaces of the missileor aircraft for enhanced aerodynamic control, maneuverability orstabilization effect. The logic devices are embedded with a hierarchicalcontrol structure to allow rapid, real-time control of fluid flow at thesurface.

The logic device(s) with the hierarchical control structure of thevarious embodiments of the present invention is composed of at least twolevels of hierarchy or structure. The lower level in various embodimentsis composed of multiple local or minor-loop feedback controllers thatmodulate the lift over discrete sections of the aerodynamic surfaces oraerodynamically-coupled surfaces and track the lift trajectoriessupplied by the global control system. The logic/control laws for thelocal controllers may be resident within local control modules. Thehigher level global control system, which in various embodiments takesas input the desired body moments and supplies as output the liftdistribution for the wing and/or other aerodynamic surfaces, necessaryto achieve the desired moments. The global control system may be eithercentralized or distributed, and therefore, its logic, may also be fullyor partially resident within one or more logic devices.

The present invention in certain specific embodiments also provides fora modular, intelligent active flow control device or activatable floweffector, and sensor that can be integrated into the missile or aircraftairframe. In other embodiments, arrays of the active flow control deviceor activatable flow effectors and sensors are used to control flowphenomena such as flow separation and reattachment on the variousaerodynamic surfaces or aerodynamically-coupled surfaces of either orboth a missile or an aircraft. In still other embodiments, a low-power,intelligent flow control system is shown, which provides aerodynamicshaping of a missile or aircraft. In still further embodiments thecontrol system is augmented with a health monitoring system.

In one embodiment, the present invention includes a missile or anaircraft comprising an aerodynamic surface or aerodynamically-coupledsurfaces; at least two air flow control zones on the same aerodynamicsurface or aerodynamically-coupled surfaces; at least one of the airflow control zones comprising at least one active flow control device oractivatable flow effector; and one or more logic devices, the logicdevices having a control system comprising separate local, closed loopcontrol system for each flow control zone, and a global control systemto coordinate the local control systems.

In another embodiment, the present invention includes a missile or anaircraft comprising an aerodynamic surface or aerodynamically-coupledsurfaces; at least two air flow control zones on the same aerodynamicsurface or aerodynamically-coupled surfaces; the at least two air flowcontrol zones each comprising at least one active flow control device oractivatable flow effector and at least one sensor having a signal; andone or more logic devices, the logic devices having a separate local,closed loop control system for each flow control zone, and a globalcontrol system to coordinate the separate, multiple input local controlsystems wherein the separate local, closed loop control system activatesand deactivates the at least one active flow control device oractivatable flow effector based on at least in part the signal of one ofthe sensors.

In still another embodiment, the present invention includes a missile oran aircraft comprising at least two air flow control zones on theaircraft or missile; at least one of the air flow control zonescomprising at least one active flow control device or activatable floweffector; and one or more logic devices, the logic devices having aseparate local, closed loop control system for each flow control zone,and a global control system to coordinate the local control systems.

In yet another embodiment, the present invention includes a missile oran aircraft comprising an aerodynamic surface or aerodynamically-coupledsurfaces; at least two air flow control zones on the same aerodynamicsurface or aerodynamically-coupled surfaces; the at least two air flowcontrol zones each comprising at least one active flow control device oractivatable flow effector; and one or more logic devices, the logicdevices having a separate local, closed loop control system for eachflow control zone for activating and deactivating the at least oneactive flow control device or activatable flow effector, and a globalcontrol system to coordinate the local control systems.

In yet another embodiment, the present invention includes a missile oran aircraft comprising at least two air flow control zones on theaircraft or missile; at least one of the air flow control zonescomprising at least one active flow control device or activatable floweffector and at least one sensor having a signal; and one or more logicdevices, the logic devices having a separate local, closed loop controlsystem for each flow control zone, and a global control system tocoordinate the local control systems wherein the separate local, closedloop control system activates and deactivates the at least one activeflow control device or activatable flow effector based on at least inpart the signal of the at least one sensor.

In yet another embodiment, the present invention includes a missile oran aircraft comprising an aerodynamic surface or aerodynamically-coupledsurfaces; at least two air flow control zones on the same aerodynamicsurface or aerodynamically-coupled surfaces; at least one of the airflow control zones comprising at least one active flow control device oractivatable flow effector and at least one sensor having a signal; andone or more logic devices, the logic devices having a separate local,closed loop control system for each flow control zone, and a globalcontrol system to coordinate the separate, multiple input local controlsystems wherein the separate local, closed loop control system activatesand deactivates the at least one active flow control device oractivatable flow effector based on at least in part the signal of the atleast one sensor.

In yet another embodiment, the present invention includes a missile oran aircraft comprising at least two air flow control zones on theaircraft or missile; the at least two air flow control zones eachcomprising at least one active flow control device or activatable floweffector and at least one sensor having a signal; and one or more logicdevices, the logic devices having a separate local, closed loop controlsystem for each flow control zone, and a global control system tocoordinate the separate, multiple input local control systems whereinthe separate local, closed loop control system activates and deactivatesthe at least one active flow control device or activatable flow effectorbased on at least in part the signal of one of the sensors.

In yet another embodiment, the present invention includes a missile oran aircraft comprising at least two air flow control zones on theaircraft or missile; the at least two air flow control zones eachcomprising at least one active flow control device or activatable floweffector; and one or more logic devices, the logic devices having aseparate local, closed loop control system for each flow control zonefor activating and deactivating the at least one active flow controldevice or activatable flow effector, and a global control system tocoordinate the local control systems.

Additional features and advantages of the invention will be set forth inthe detailed description which follows, and in part will be readilyapparent to those skilled in the art from that description or recognizedby practicing the invention as described herein, including the detaileddescription which follows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are merely exemplary of theinvention, and are intended to provide an overview or framework forunderstanding the nature and character of the invention as it isclaimed. The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate various embodimentsof the invention, and together with the description serve to explain theprinciples and operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. Flow diagram for a fixed, cascade controller for local controlof an individual active flow control device or activatable floweffector.

FIG. 2. Flow diagram for a fixed, output feedback controller for localcontrol of an individual active flow control device or activatable floweffector.

FIG. 3. Flow diagram for an adaptive, cascade controller for localcontrol of an individual active flow control device or activatable floweffector.

FIG. 4. Flow diagram of an adaptive, output controller for local controlof an individual active flow control device or activatable floweffector.

FIG. 5. Flow diagram of a fixed, cascade controller for global controlof an aircraft or missile.

FIG. 6. Flow diagram of a fixed, output controller for global control ofan aircraft or missile.

FIG. 7. Flow diagram of an adaptive, cascade controller for globalcontrol of an aircraft or missile.

FIG. 8. Flow diagram of an adaptive, output feedback controller forglobal control of an aircraft or missile.

FIG. 9. Flow diagram of an aircraft or missile hierarchical controlsystem with a distributed global controller.

FIG. 10. Flow diagram of an aircraft or missile hierarchical controlsystem with a centralized, cascade global controller with minor loopcascade feedback loops for local control of individual activatable floweffectors.

FIG. 11. Flow diagram of an aircraft or missile hierarchical controlsystem with a centralized, cascade global controller with minor loopoutput feedback loops for local control of individual active flowcontrol device or activatable effectors.

FIG. 12. Flow diagram of an aircraft or missile hierarchical controlsystem with a centralized, cascade global controller with minor loopadaptive cascade feedback loops for local control of individual activeflow control device or activatable flow effectors.

FIG. 13. Flow diagram of an aircraft or missile hierarchical controlsystem with a centralized, cascade global controller with minor loopadaptive output feedback loops for local control of individual activeflow control device or activatable flow effectors.

FIG. 14. Flow diagram for a airflow control system health monitoringsystem as it relates to computing feedback commands.

FIG. 15. Flow diagram for an aircraft or missile hierarchical controlsystem with a centralized, cascade global controller with minor loopadaptive cascade feedback loops for local control of individual activeflow control device or activatable flow effectors.

FIG. 16. Flow diagram for an aircraft or missile hierarchical controlsystem with a centralized, cascade global controller with minor loopadaptive output feedback loops for local control of individual activeflow control device or activatable flow effectors.

FIG. 17. Flow diagram for an adaptive, cascade controller for globalcontrol of a missile or aircraft that has been augmented with the healthmonitoring system shown in FIG. 14.

FIG. 18. Flow diagram for an adaptive, output controller for globalcontrol of a missile or aircraft that has been augmented with the healthmonitoring system shown in FIG. 14.

FIG. 19. Flow diagram for an aircraft or missile hierarchical controlsystem with a distributed controller that has been augmented with thehealth monitoring system shown in FIG. 14.

FIG. 20. Flow diagram for a predictive, adaptive cascade controller forlocal control of an individual active flow control device or activatableflow effector.

FIG. 21. Flow diagram for a predictive, adaptive output feedbackcontroller for local control of an individual active flow control deviceor activatable flow effector.

FIG. 22. Flow diagram for a predictive, adaptive, cascade controller forglobal control of an aircraft or missile.

FIG. 23. Flow diagram for a predictive, adaptive, output feedbackcontroller for global control of an aircraft or missile.

FIG. 24. Flow diagram for an aircraft or missile hierarchical controlsystem with a centralized, cascade global controller with minor looppredictive adaptive cascade feedback loops for local control of theindividual active flow control device or activatable flow effectors.

FIG. 25. Flow diagram for an aircraft or missile hierarchical controlsystem with a centralized, cascade global controller with minor looppredictive adaptive output feedback loops for local control of theindividual active flow control device or activatable flow effectors.

FIG. 26. Flow diagram for an aircraft or missile hierarchical controlsystem with a centralized, cascade global controller with minor looppredictive adaptive cascade feedback loops for local control of theindividual active flow control device or activatable flow effectors thatis augmented with the health monitoring system shown in FIG. 14.

FIG. 27. Flow diagram for an aircraft or missile hierarchical controlsystem with a centralized, cascade global controller with minor looppredictive adaptive output feedback loops for local control of theindividual active flow control device or activatable flow effectors thatis augmented with the health monitoring system shown in FIG. 14.

FIG. 28. Flow diagram for a predictive, adaptive, cascade controller forglobal control of an aircraft or missile that is augmented with thehealth monitoring system shown in FIG. 14.

FIG. 29. Flow diagram for a predictive, adaptive, output feedbackcontroller for global control of an aircraft or missile that isaugmented with the health monitoring system shown in FIG. 14.

FIG. 30. Schematic view of one embodiment of a missile having multipleflow control zones, a number of the airflow control zones being onaerodynamically-coupled surface.

FIG. 31. Schematic view of one embodiment of an aircraft having multipleflow control zones, a number of the airflow control zones being on thesame aerodynamic surface.

FIG. 32. Perspective view of a wing similar to the wing 24 of theaircraft 20 shown in FIG. 31.

FIG. 33. Sectional view of section A-A′ of the aircraft wing as shown inFIG. 32.

FIG. 34A-B. Perspective view of one embodiment of a module containing aco-located sensor, and A) a deployable flow effector (deployed) and B) adeployable flow effector (retracted).

FIG. 35. Sectional view of one embodiment of a deployable flow effector.

FIG. 36A-D. Sectional view of deployable flow effector shapes.

FIG. 37. Sectional view of another embodiment of a deployable floweffector.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to a missile or aircraft with ahierarchical, closed-loop flow control system and more particularly toaircraft or missile with a flow control system for aerodynamic control,maneuverability and stabilization. The present invention further relatesto a method of operating the flow control system. The present inventioninvolves the airflow control or flow control on any aerodynamic surface,aerodynamically-coupled surfaces or any combination of aerodynamicsurfaces on a missile or aircraft including but not limited to liftsurface control, forebody control, afterbody control and any combinationthereof. The forebody herein is described as the front half of themissile or aircraft or that portion in front of the lift surfaces, i.e.,the wings. Preferably, the forebody is the front 25% of the length ofthe missile or aircraft, and most preferably the forebody is the nose ofthe missile or aircraft. The nose of the missile or aircraft is the coneshaped leading edge. The afterbody herein is described as the back halfof the missile or aircraft or that portion behind the lift surfaces,i.e., the wings. Preferably, the afterbody is the back 25% of the lengthof the missile or aircraft, and most preferably the afterbody is thetail section of the missile or aircraft including but not limited to thetail fins and boattail.

The aerodynamic surfaces of the various embodiments of the presentinvention are those surfaces over which the airflow moves during theflight of the missile or aircraft. Aerodynamically-coupled surfaces arethose surfaces which are aerodynamically linked by airflow. Preferably,aerodynamically-coupled surfaces are those surfaces which are joinedtogether over which the airflow moves during the flight of the missile,aircraft or munition. An example of aerodynamically-coupled surfaces area wing and the fuselage of the missile or aircraft. Another example ofaerodynamically-coupled surfaces is a control surface on a missile ormunition when it is attached or just released from an aircraft andchanges in the flow over the aircraft impact the flow over the attachedor just released missile or munition.

The flow effectors of the various embodiments of the present inventioninclude any or both active flow control device or activatable floweffectors, and traditional control surfaces. The active flow controldevice or activatable flow effectors of the present invention includeany electromechanical devices that can induce flow perturbation viaeither, mass, momentum, or energy transfer into the flow field aroundthe surface of a missile or an aircraft. Preferably, the active flowcontrol device or activatable flow effectors create small disturbancesin the vicinity or close proximity to the actuator. Further preferably,the active flow control device or activatable flow effector is flush oris nearly flush, when deactivated, with the surface of the missile oraircraft to which it has been installed thereby creating little to nodrag from the device or effector itself on the munition, missile oraircraft. Still further preferably, the active flow control device oractivatable flow effectors have no hinged parts or surfaces exposed tothe airflow. The active flow control device or activatable floweffectors of the present invention include but are not limited to activevortex generators, which are deployable or create pressure activeregions by suction or air pressure; synthetic jets; pulsed vortexgenerators; plasma actuators including weakly ionized plasma actuators;wall turbulators; porosity including but not limited to inactive andactive; microactuators; and thermal actuators. The present inventionfurther relates to a method of operating the flow control system.

The flow control system for stabilization and maneuverability of themissile or aircraft afterbody relies on the effectiveness of the ingenerating on-demand forces at different points around the missile oraircraft afterbody to create the desired control effect. The flowcontrol system for the missile or aircraft afterbody can be used at bothlow and high angles of attack. The active flow control devices oractivatable flow effectors of the present invention include activemicro-vortex generators that effectively control the pressuredistribution along the aerodynamic surfaces of a missile, munition oraircraft, yielding forces and yawing, rolling and pitching moments forcontrolling of yaw, roll or pitch on the munition, missile or aircraftbody. The active flow control devices or activatable flow effectors ofthe present invention preferably are deployable flow effectors or othertypes of micro-vortex generators. Active flow control devices oractivatable flow effectors of the present invention are flow effectorsthat are activated to generate fluid flow disturbances in the vicinityof the flow effector, and that can be deactivated when not needed.Preferably, the active flow control device or activatable flow effectorsof the present invention can be activated and deactivated at highfrequencies.

Preferably, active flow control devices or activatable flow effectorscan produce modulated disturbances or be operated in a binary manner.Further preferably, if operated in a binary manner the active flowcontrol devices or activatable flow effectors can be cycled at variousfrequencies. Further preferably, the active flow control device oractivatable flow effectors are capable of being cycled at frequencies ofat least about 1 Hz, more preferably at frequencies of at least about 20Hz, even more preferably at frequencies of at least about 60 Hz, evenmore preferably at frequencies of at least about 100 Hz, and mostpreferably at frequencies of at least about 250 Hz. Deployable floweffectors, one type of active flow control device or activatable floweffectors, are described in more detail in the various embodiments inthe Figures below. The frequencies at which the flow effectors of thepresent invention are cycled may be determined based in part on a numberof factors including but not limited to autopilot frequency responsecharacteristics, missile or aircraft dynamics, and missile or aircraftenvironmental conditions. Actuators such as distributed porosity orsuction based systems are nominally binary devices in that eachindividual or groups of holes may be turned on or off on an individualbasis, however these systems may also be operated in a larger aggregategroup, thereby forming a single active flow control device or activeableflow effector which is capable of producing modulated flow responses.

Some of the other types of activatable flow effectors not shown in theFigures (but described in more detail in U.S. Pat. No. 6,302,360 B1 toNg which is herein incorporated by reference) include spaced apartvalves that are positioned at inlets of a vacuum or pressure chamber, orare connected by pneumatics to a vacuum or pressure source. Preferably,the valves contain a flap that operates to open and close the valves asdirected by electrostatic forces. Other valve configurations can also beused. When the valves are opened, the negative pressure from the vacuumchamber or source causes withdrawal of air from the surface of themissile or aircraft forebody through the surface orifices. Therefore, itcan be seen that the opening of the valves causes the pressure activeregion to generate a net inflow of air from the upper flow of airtraveling across the surface of the missile or aircraft afterbody. Thisnet inflow of air causes a disturbance in the upper flow, resulting inthe generation of vortices, which act beneficially to stabilize theairflow over the aerodynamic surface or aerodynamically-coupled surfacesof the munition, missile or aircraft, or to create commanded forces onthe missile or aircraft afterbody to improve maneuverability and/orstability. Similarly, when the valves are open to a positive pressurechamber or source, a net outflow of air is generated resulting in thegeneration of vortices, which also act beneficially to create forces orreattach the air flow to the aerodynamic surface(s) of the munition,missile or aircraft. For purposes of this invention flow effectorsinclude any type of device or article known to those skilled in the artor discovered at a later point that is used to assist in the creation offorces or reattachment of airflow to a munition, missile or aircraftssurface. Preferably, the active flow control devices or activatable floweffectors of the present invention are deployable flow effectors.Further preferably, the missile or aircraft of the present invention hasat least about 4 activatable flow effectors, more preferably at leastabout 6 activatable flow effectors, even more preferably at least about8 activatable flow effectors, still even more preferably at least about50, and most preferably at least about 200.

The applicants further incorporate by reference U.S. Pat. No. 6,837,465B2, which was issued on Jan. 4, 2005 and U.S. Pat. No. 6,866,233 B2,which was issued on Mar. 15, 2005.

The sensor(s) of the present invention include but are not limited to adynamic pressure sensor, shear stress sensor (hot film anemometer, adirect measurement floating-element shear stress sensor), inertialmeasurement unit or system, and other sensors known to those skilled inthe art whose signal could be used to estimate or determine a flowcondition on the surface of the missile or aircraft, which wouldfunction as a trigger point for actuating the flow control actuator. Thesensors of the present invention can be used to determine or estimateflow separation. An inertial measurement unit for example is a sensor,which would not directly measure forces or flow separation, but can beused to estimate or predict separation. The preferred sensor of thepresent invention is a pressure sensor. The pressure sensor can be anytype of sensor suitable for measuring the pressure at the flow surface.The pressure sensor can for example be a piezoelectric device, whichgenerates an electric signal in response to a sensed pressure, a shapememory alloy device, or any other pressure sensor or transducer known tothose skilled in the art. Preferably, the ratio of flow effectors tosensors is less than about 100:1, more preferably less than or equal toabout 50:1, still preferably less than or equal to about 20:1, even morepreferably less than or equal to about 3:1, still even more preferablyless than or equal to about 2:1, and most preferably less than or equalto 1:1. The higher the concentration of pressure sensors to floweffectors the more redundancy and/or sensitivity can be built into thesystem utilizing the present invention. Most preferably the sensor is aflush, surface mounted diaphragm type pressure sensor. The at least onesensor 14 having a signal which is used at least in part by a controller(not shown) to activate and deactivate the at least one active flowcontrol device or activatable flow effector 12.

In addition to pressure sensors, various embodiments of the presentinvention may also include a means for determining the relative spatialorientation of the flow effectors and/or sensors on the missile oraircraft body. This means would include utilizing the output of aninertial measurement unit and other systems, including but not limitedto horizon sensors, satellite and mobile reference transmitters such asGlobal Positioning Systems (GPS), and magnetometers, which could be usedto determine the missile or aircraft orientation. An inertialmeasurement unit provides six-degree-of-freedom motion sensing forapplications such as navigation and control systems. Angular rate andacceleration are measured about three orthogonal axes.

The airflow control zone(s) of various embodiments of the presentinvention is a discrete area or region of an aerodynamic surface of themissile or aircraft. The airflow control zone(s) preferably comprises atleast one active flow control device or activatable flow effector overwhich the airflow is locally controlled by the logic devices to bedescribed further in this application. The airflow control zone(s), morepreferably, further comprises at least one sensor having a signal.Preferably, the missile or aircraft comprises at least about 2 airflowcontrol zones, more preferably at least about 4 airflow control zones,even more preferably at least about 8 airflow control zones, even morepreferably at least about 16 airflow control zones, even more preferablyabout 32 airflow control zones, even more preferably at least about 64airflow control zones, even more preferably about 128 airflow controlzones, and most preferably at least about 256 airflow control zones.Preferably, the aerodynamic surface or aerodynamically-coupled surfacesof the missile or aircraft of the present invention comprise at leastabout 2 airflow control zones, more preferably at least about 3 airflowcontrol zones, even more preferably at least about 4 airflow controlzones, even more preferably at least about 6 airflow control zones, evenmore preferably at least about 10 airflow control zones, even morepreferably at least about 16 airflow control zones, even more preferablyat least about 24 airflow control zones, and most preferably at leastabout 40 airflow control zones. The airflow control zones may include anairflow control zone or zones, which include, utilize, or work inconjunction with traditional flow control devices and surfaces such asflaps and slats. At least one of the airflow control zones comprises atleast one active flow control device or activatable flow effector.

The logic device(s) of the various embodiments of the present inventioninclude either or both analog and digital circuits. Preferably, thelogic device(s) is a digital circuit. The logic devices include but arenot limited to computers, microprocessors, control circuits, fieldprogrammable gate arrays, programmable logic chips, analog computers,micro-controllers, and the like. Preferably, the missile or aircraft ofthe present invention comprises one or more logic devices that arepartially or fully utilized for controlling the airflow over theaerodynamic surface(s) of the missile or aircraft. The one or more logicdevices comprise a hierarchical control structure. This controlstructure comprises a separate local, closed loop control system foreach flow control zone and a global control system to coordinate theaction of the local control systems.

This hierarchical control structure comprises hierarchical algorithmarchitectures embedded within the one or more logic devices which arecategorized in several ways. Preferably, the control system includinga11 elements of the system controlling the airflow zones possess aninput/output structure. That is, specific inputs to the control systemexist which can affect the output of the control system, which is somemeasurable behavior(s) (i.e., control command). In addition, preferablythe control system has memory, or dependence upon previous conditionsand inputs. The memory of the control system preferably is described bythe system state a parameter(s) that describes or captures the physicalcharacteristics of the system. For instance, for controlling theposition of or the flow around the aircraft or missile, the input to thecontrol system could be a quality of the airflow, i.e., pressure,velocity, etc across an aerodynamic surface, the output would then be alevel of actuator effort (in our case the active flow control device oractivatable flow effector).

The algorithms may be categorized in terms of the type of informationused to formulate the control directives. Under this system ofclassification, the control architectures are cascade algorithms oroutput feedback algorithms. In cascade algorithms, the system output isused directly to compute an error signal (the difference between thedesired and measured/observed behaviors) that is the basis of thecontroller's action. Conversely, output feedback algorithms compute afeedback signal based upon the system output which is in turn used tocompute an error signal and hence the control action. In many cases,cascade algorithms are state feedback algorithms where the control inputis based upon the state (either directly measured or obtained via anobserver) of the system.

Another classification is based upon the constancy of the controllerparameters. Under this taxonomy, the controller may be described as afixed controller or as an adaptive controller. It should be noted thatthis distinction is not necessarily clear-cut. For instance, gainscheduling controllers will change the controller parameters accordingto a fixed schedule, that is, in one region of a system's operationalenvelope, one set of controller parameters will be used. If the systemthen moves into another region of the operational envelope, a new set ofparameters will be obtained from a look up table, or schedule, andsubstituted. In this scenario, the parameters are changed open loop,there is no feedback loop modulating the controller parameters. Despitethe fact that the controller parameters change, a gain schedulingcontroller is still classified as a fixed gain controller because thechanges are performed open loop. The defining characteristic of adaptivecontrollers is that a second, outer feedback loop is used to control thevariations of the controller parameters. A subclassification of adaptivecontrollers is the predictive controller that uses some adaptive modelto predict the future behavior at some fixed time ahead, known as thecontrol horizon, and determines the appropriate control action basedupon the predicted future behavior.

The control algorithm may also be characterized in terms of themathematical structure of the control law. If the control input is alinear combination of the error and its derivatives (or of the statevariables or measured variables) the controller is said to be a linearcontroller and the coefficients used to construct this linearcombination are known as the controller gains. Otherwise, the controlleris said to be a nonlinear controller.

The manner in which the control input is computed also gives rise to ataxonomy. For many complex systems, multiple inputs exist. For example,to control the virtual aerodynamic shape of an aerodynamic surface (suchas a wing), it may be necessary to have a large number of individualactivatable flow effectors. If all of the different inputs are computeden masse in an individual process, the controller is said to be acentralized controller. If each of the individual inputs or distinctgroups of inputs are determined via independent processes, thecontroller is known as a distributed or decentralized controller. Notethat this nomenclature refers to the architecture of the control system,not the process or system itself, it is possible to design a centralizedcontroller for a distributed system such as a large number of actuatorsdistributed over the surface of an aerodynamic surface. A centralizedcontrol algorithm is typically much easier to design and implement thana distributed one, unfortunately, these algorithms are sometimesexecuted on an single processor and hence there is a limit to the numberof inputs that may be effectively controlled in order to control themissile or aircraft in real-time. Another disadvantage of centralizedcontrol systems is the difficulty of running control lines fordistributed actuators (flow effectors) and/or sensors back to a singlecontrol system. Distributed algorithms, on the other hand, may beexecuted on multiple processors simultaneously and hence can be scaledto accommodate large numbers of inputs. It must be clarified, also, thatthis nomenclature refers to the algorithm itself, not the hardware uponwhich it is executed. With a distributed controller, it is possible toexecute several independent processes on an individual processorsimultaneously and hence, a one to one correlation between processes andprocessors is not a requirement for a distributed control system.

Finally, within a control system, a classification is required todescribe its hierarchy. If a control system regulates the behavior ofonly a portion of the system, it is called a local controller. The localcontroller manages the airflow control zone(s) or the individual floweffectors. Conversely, if the control system is responsible forcontrolling the entire system, it is a global controller. It is possibleto have a distributed global control system. In this case, a set ofdistributed, local controllers may comprise the global controller forthe entire system. Often, local controllers may be combined with aglobal controller to form a hierarchical control system. In this case,an outer control loop may be constructed to coordinate the behaviors oflocal controllers. This outer most loop is commonly referred to as theglobal controller within the context of a hierarchical control system.It is not necessary that the global controller be a classical feedbacksystem, it may be an expert system, a fuzzy logic system or a simplerule base. In addition, nontraditional approaches may also be used suchas artificial neural networks may be used as a global controller. If aclosed loop feedback controller is used as a global controller, anylocal feedback loops present are known as minor feedback loops. It isalso possible that the hierarchical control system possesses more thantwo layers, minor feedback loops can themselves have minor feedbackloops and a local controller may coordinate even more localizedcontrollers. For example, an airplane may have a global control systemthat controls two wings, each of the wings may have a local controllerthat in turn coordinates the behavior of multiple flow effectors on thesurface of the wing, each of which are regulated by its own localcontroller.

FIGS. 1 through 29 are flow diagrams outlining a number of embodimentsof the control structure or portions thereof that is programmed ordesigned into the one or more logic devices. While many of the controlstructures are used to control individual flow effectors. Thesestructures are also envisioned to control airflow control zones withmultiple flow effectors, which includes active flow control devices oractivatable flow effectors and traditional flow control surfaces.

FIG. 1 is a flow diagram for a fixed, cascade controller 210 for localcontrol of an individual flow effector. An input command 212 isspecified in some manner, usually from the global control system (notshown). This control input is then compared with some measured output ofthe effect of the flow effector such as a down stream pressuremeasurement and an error 214 (and

possibly derivatives and integrals of the error) is computed. Based uponthe computed error, an input to the flow effector is determined 216 andinput 218. The effect of this actuation is measured and returned forcomparison 220 with the input command. Note, this is not necessarily adiscrete event algorithm, it may be continuous or a digitalapproximation to a continuous process. The input command may be acontinuously varying signal or its digital analog, or a discrete signal.

FIG. 2 is a flow diagram for a fixed, output feedback controller 222 forlocal control of an individual flow effector. An input command 224 isspecified in some manner, usually from some global control system (notshown). This control input is then augmented by some computed feedbackinput 226 based upon some measured output from the flow effector such asa down stream pressure. The augmented input is then used to drive theflow effector 228. The effect of this actuation is measured 230 andpassed to a control law 232 for computation of the feedback signal.Note, this is not necessarily a discrete event algorithm, it may becontinuous or a digital approximation to a continuous process. The inputcommand may be a continuously varying signal or its digital analog, or adiscrete signal.

FIG. 3 is a flow diagram for an adaptive, cascade controller 240 forlocal control of an individual flow effector. An input command 242 isspecified in some manner, usually from some global control system (notshown) to both an inner loop 241 that determines the input to the floweffector and to an outer loop 244 that determines the control law usedto compute the flow effector input. The inner and outer loops runconcurrently, though the processing rates for the two loops need not bethe same. In the inner loop, the control input is compared with somemeasured output 246 from the flow effector such as a down streampressure and an error (and possibly derivatives and integrals of theerror) is computed. Based upon the computed error 246, an input to theflow effector is determined 248 and input 250. The effect of thisactuation is measured and returned for comparison 252 with the inputcommand. Concurrently, the output is also passed to the outer loop 252.The outer loop uses the input 242 and corresponding output to determinethe accuracy of the model 254 used for the control law design. Both thestructure of the system model 256 and the control law design process 258are also inputs to the adaption scheme used in the outer loop. Basedupon the measure of model accuracy, the control law is adapted 260.Several mechanisms are available for use in control law adaption such assystem identification based schemes and stability law schemes. Note,this is not necessarily a discrete event algorithm, it may be continuousor a digital approximation to a continuous process. The input commandmay be a continuously varying signal or its digital analog, or adiscrete signal.

FIG. 4 is a flow diagram for an adaptive, output feedback controller 270for local control of an individual flow effector. An input command 272is specified in some manner, usually from some global control system(not shown) to both an inner loop 274 that determines the input to theflow effector and to an outer loop 276 that determines the control lawused to compute the flow effector input. The inner and outer loops runconcurrently, though the processing rates for the two loops need not bethe same. In the inner loop 274, the control input is then augmented bysome computed feedback input 278 based upon some measured output fromthe flow effector such as a down stream pressure. The augmented input isthen used to drive 280 the flow effector. The effect of this actuationis measured 282 and passed to a control law 284 for computation of thefeedback signal. Concurrently, the output 282 is also passed to theouter loop 276. The outer loop 276 uses the input 272 and correspondingoutput 282 to determine the accuracy of the model used for the controllaw design. Both the structure of the system model 286 and the controllaw design process 288 are also inputs to the adaption scheme used inthe outer loop. Based upon the measure of model accuracy, the controllaw is adapted 290. Several mechanisms are available for use in controllaw adaption such as system identification based schemes and stabilitylaw schemes. Note, this is not necessarily a discrete event algorithm,it may be continuous or a digital approximation to a continuous process.The input command may be a continuously varying signal or its digitalanalog, or a discrete signal.

FIG. 5 is a flow diagram for a fixed, cascade controller 300 for globalcontrol of an aircraft or missile. An input command 302 is specified insome manner, usually from some global control system, e.g., desired bodyrates from an autopilot or a human operator. This control input 302 isthen compared 304 with some measured output 306 from the aircraft ormissile such as the aircraft body rates (roll, pitch and yaw), and anerror (and possibly derivatives and integrals of the error) is computed304. Based upon the computed error, an input 308 to all of the floweffectors is determined and input 310. The effect of this actuation ismeasured 306 and returned for comparison with the input command 304.Note, this is not necessarily a discrete event algorithm, it may becontinuous or a digital approximation to a continuous process. The inputcommand may be a continuously varying signal or its digital analog, or adiscrete signal.

FIG. 6 is a flow diagram for a fixed, output feedback controller 320 forglobal control of an aircraft or missile. An input command 322 isspecified in some manner, usually from some global control system. Thiscontrol input 322 is then augmented 328 by some computed feedback input324 based upon some measured output from the aircraft 326 such as theaircraft body rates (roll, pitch and yaw). The augmented input 330 isthen used to drive all of the flow effectors. The effect of thisactuation is measured 326 and passed to a control law for computation ofthe feedback signal. Note, this is not necessarily a discrete eventalgorithm, it may be continuous or a digital approximation to acontinuous process. The input command may be a continuously varyingsignal or its digital analog, or a discrete signal.

FIG. 7 is a flow diagram for an adaptive, cascade controller 340 forglobal control of an aircraft or missile. An input command 342 isspecified in some manner, usually from some global control system toboth an inner loop 344 that determines the input to the flow effectorand to an outer loop 346 that determines the control law used to computethe flow effector input. The inner 344 and outer 346 loops runconcurrently, though the processing rates for the two loops need not bethe same. In the inner loop, the control input is compared with somemeasured output 348 from the aircraft or missile such as the aircraft ormissile body rates (roll, pitch and yaw), and an error (and possiblyderivatives and integrals of the error) is computed 350. Based upon thecomputed error 350, the input to all of the flow effectors is determined352 and input 354. The effect of this actuation is measured and returned348 for comparison with the input command 342. Concurrently, the output354 is also passed to the outer loop 346. The outer loop 346 uses theinput 342 and corresponding output 354 to determine the accuracy 356 ofthe model used for the control law design 358. Both the structure of thesystem model 360 and the control law design 358 process are also inputsto the adaption scheme used in the outer loop. Based upon the measure ofmodel accuracy, the control law is adapted and updated 362. Severalmechanisms are available for use in control law adaption such as systemidentification based schemes and stability law schemes. Note, this isnot necessarily a discrete event algorithm, it may be continuous or adigital approximation to a continuous process. The input command may bea continuously varying signal or its digital analog, or a discretesignal.

FIG. 8 is a flow diagram for an adaptive, output feedback controller 370for global control of an aircraft or missile. An input command 372 isspecified in some manner, usually from some global control system (notshown) to both an inner loop 374 that determines the input to the floweffector and to an outer loop 376 that determines the control law usedto compute the flow effector input 378. The inner 374 and outer loops376 run concurrently, though the processing rates for the two loops neednot be the same. In the inner loop 374, the control input 372 is thenaugmented 378 by some computed feedback input 380 based upon somemeasured output 382 from the aircraft or missile such as the aircraft ormissile body rates (roll, pitch and yaw). The augmented input 378 isthen used to drive 384 all of the flow effectors. The effect of thisactuation is measured and passed to a control law for computation of thefeedback signal. Concurrently, the output 382 is also passed to theouter loop 376. The outer loop 376 uses the input 372 and correspondingoutput 382 to determine the accuracy of the model used for the controllaw design 386. Both the structure of the system model 388 and thecontrol law design 386 process are also inputs to the adaption scheme390 used in the outer loop. Based upon the measure of model accuracy,the control law is adapted and updated 392. The updated controlparameters are then impact the inner loop 374 by changing thecomputation of feedback 380. Several mechanisms are available for use incontrol law adaption such as system identification based schemes andstability law schemes. Note, this is not necessarily a discrete eventalgorithm, it may be continuous or a digital approximation to acontinuous process. The input command may be a continuously varyingsignal or its digital analog, or a discrete signal.

FIG. 9 is a flow diagram for a hierarchical control system 400 with adistributed global controller. In the outer loop 402, measured bodyrates 404 are compared 408 with some specified desired body rates 406(position, velocity, orientation . . . ). The desired body rates 406(position, velocity, orientation . . . ) may be specified by anothercontrol system such as for example an autopilot (not shown), by a humanoperator (not shown), or a pilot (not shown). Any preprocessing 410 ofthe input and feedback data, such as computation of rate errors isperformed next and passed 412 to all of the distributed processes thatcomprise the global control system for the aircraft via a bus. Basedupon this global information, the distributed controller determines theappropriate local behavior and passes corresponding commands 414 toassociated behavioral control modules 416. Note that each of theseindependent processes is associated with at least one behavioral controlmodule 416. The behavioral control module shown here, examines sensordata 418 from both itself 422 and from 0 to p neighbors 420, where p isany positive integer up to the number of flow control zones, and polls426 the neighbors to determine what actions its neighbors are taking424. The behavioral control modules 416 associated with the other inputcommands has not been expanded as it has for the ith local controller422. The content of these behavioral control modules 416 is identical tothat of the one shown for the ith behavioral control module 422. Basedupon the desired behavior and the information 418, 426 determined fromits neighbors, an input to the local flow effector is computed 428 andapplied 430. In essence, the behavioral control module is a localcontroller that uses only local information to determine input to theflow effectors though the definition of local information is extended topossibly include input/output information from neighboring behavioralcontrol modules. It must be noted that the neighboring behavioralcontrol modules are not necessary adjacent modules but may beaerodynamically coupled in some manner. It is also noteworthy that thelocal control algorithm used within the behavioral control module is notconstrained to be a traditional feedback control system but may also bea non-traditional control algorithm such as an expert system, a swarmintelligence-based algorithms or neural reflex. The net effect of theactuation from all of the flow effectors is then measured via sensor andpassed back for comparison with the desired body rates (position,velocity, orientation . . . ).

FIG. 10 is a flow diagram for a hierarchical control system with acentralized, cascade global controller with minor loop cascade feedbackloops for local control of the individual flow effectors 440. In theoutermost loop 442, a desired set of body rates 444 (position, velocity,orientation . . . ) is specified either by another control system suchas an autopilot (not shown), a human operator (not shown) or pilot (notshown) and compared 448 with the sensed body rates 446 (position,velocity, orientation . . . ) of the aircraft or missile. The controllerdetermines 450 the appropriate behavior such as desired lift for eachairflow control zone 452 and transmits 454 these behaviors as commandsto each of the local, minor loop feedback controllers 456. The localcontroller 456 shown here is identical to that shown in FIG. 1 andoperates in precisely the same manner to produce the appropriateactuator input. The local control modules associated with the otherinput commands has not been expanded as it has for the ith localcontroller 458. The content of these local controllers is identical tothat of the one shown for the ith local control module. The net effectof the actuation from all of the flow effectors is then measured viasensors and passed back for comparison with the desired body rates(position, velocity, orientation . . . ).

FIG. 11 is a flow diagram for a hierarchical control system with acentralized, cascade global controller with minor loop output feedbackloops for local control of the individual flow effectors 460. In theoutermost loop 462, a desired set of body rates 464 (position, velocity,orientation . . . ) is specified either by another control system suchas an autopilot (not shown), a human operator (not shown), or pilot (notshown) and compared 467 with the sensed body rates 466 (position,velocity, orientation . . . ) of the aircraft or missile. The controller468 determines the appropriate behavior such as desired lift for eachairflow control zone 470 and transmits 472 these behaviors as commandsto each of the local, minor loop feedback controllers 474. The localcontroller shown here is identical to that shown in FIG. 2 and operatesin precisely the same manner to produce the appropriate actuator input.The local control modules 474 associated with the other input commandshas not been expanded as it has for the ith local controller 476. Thecontent of these local controllers 474 is identical to that of the oneshown for the ith local control module 476. The net effect of theactuation from all of the flow effectors is then measured via sensor andpassed back for comparison with the desired body rates (position,velocity, orientation . . . ).

FIG. 12 is a flow diagram for a hierarchical control system with acentralized, cascade global controller with minor loop adaptive cascadefeedback loops for local control of the individual flow effectors 480.In the outermost loop 482, a desired set of body rates 484 (position,velocity, orientation . . . ) is specified either by another controlsystem such as an autopilot (not shown), a human operator (not shown) orpilot (not shown) and compared 488 with the sensed body rates 486(position, velocity, orientation . . . ) of the aircraft or missile. Thecontroller determines 490 the appropriate behavior such as desired liftfrom each airflow control zone 492 and transmits 494 these behaviors ascommands to each of the local, minor loop feedback controllers 496. Thelocal controller 496 shown here is identical to that shown in FIG. 3 andoperates in precisely the same manner to produce the appropriateactuator input. The local control modules 496 associated with the otherinput commands has not been expanded as it has for the ith localcontroller 498. The content of these local controllers 496 is identicalto that of the one shown for the ith local control module 498. The neteffect of the actuation from all of the flow effectors is then measuredvia sensor and passed back for comparison with the desired body rates(position, velocity, orientation . . . ).

FIG. 13 is a flow diagram for a hierarchical control system with acentralized, cascade global controller with minor loop adaptive outputfeedback loops for local control of the individual flow effectors 500.In the outermost loop 502, a desired set of body rates 504 (position,velocity, orientation . . . ) is specified either by another controlsystem such as an autopilot (not shown), a human operator (not shown) orpilot (not shown) and compared 508 with the sensed body rates 506(position, velocity, orientation . . . ) of the aircraft or missile. Thecontroller 510 determines the appropriate behavior such as desired liftfor each airflow control zone 512 and transmits 514 these behaviors ascommands to each of the local, minor loop feedback controllers 516. Thelocal controller 516 shown here is identical to that shown in FIG. 4 andoperates in precisely the same manner to produce the appropriateactuator input. The local control modules 516 associated with the otherinput commands has not been expanded as it has for the ith localcontroller 518. The content of these local controllers 516 is identicalto that of the one shown for the ith local control module 518. The neteffect of the actuation from all of the flow effectors is then measuredvia sensor and passed back for comparison with the desired body rates(position, velocity, orientation . . . ).

FIG. 14 is a flow diagram for a schematic of a health monitoring system520 as it relates to computing feedback commands. The implementation ofthis health monitoring system with specific control schemes is shown inmore detail in the following figures. The health monitoring scheme is anadjunct to control law adaption 522. As the adaption process involvesdetecting or at least implicitly detecting changes in the system, it isa natural place to monitor for systemic failures and degradation. Theoutput of the adaption scheme is passed 524 to the health monitoringprocess 526 as well as to the control law computation 528. The healthmonitoring system 520 is composed of pattern recognition algorithms (notshown) including artificial neural networks, time/frequency analysis,wavelet analysis, fuzzy logic, etc., and a decision system (not shown)such as an expert system or fuzzy logic system. The output from thehealth monitoring system is passed to the user interface 530 for use bythe automatic pilot (not shown), human operator (not shown) or pilot(not shown) of the aircraft or missile. In addition, the output of thehealth monitoring system can be passed to the adaption algorithm toprovide a new control law design methodology 532 and updated systemmodel 534 so that a “limp home” mode can be enabled for the aircraftthat uses alternative actuation/sensing strategies for control. Forexample, the loss of full use of a flap may necessitate the use of skidto turn maneuvers instead of bank to turn maneuvers.

FIG. 15 is a flow diagram for a hierarchical control system 540 with acentralized, cascade global controller with minor loop adaptive cascadefeedback loops for local control of the individual flow effectors thathas been augmented with the health monitoring system shown in FIG. 14.This controller is identical to that shown in FIG. 12 and operates inprecisely the same manner except that the adaption information 542 ismade available to a global health monitoring system 544. Note that thescope of the health monitoring system is global though only anindividual instance is shown for an individual local controller. Theother local controllers shown in the figure have the same structure asthe expanded controller shown for the ith local controller and thehealth monitoring system is the same, global system for each.

FIG. 16 is a flow diagram for a hierarchical control system 550 with acentralized, cascade global controller with minor loop adaptive outputfeedback loops for local control of the individual flow effectors thathas been augmented with the health monitoring system shown in FIG. 14.This controller is identical to that shown in FIG. 13 and operates inprecisely the same manner except that the adaption information 552 ismade available to a global health monitoring system 554. Note that thescope of the health monitoring system is global though only anindividual instance is shown for an individual local controller. Theother local controllers shown in the figure have the same structure asthe expanded controller shown for the ith local controller and thehealth monitoring system is the same, global system for each.

FIG. 17 is a flow diagram for an adaptive, cascade controller for globalcontrol of an aircraft or missile 560 that has been augmented with thehealth monitoring system shown in FIG. 14. This controller is identicalto that shown in FIG. 7 and operates in precisely the same manner exceptthat the adaption information 562 is made available to a global healthmonitoring system 564.

FIG. 18 is a flow diagram for an adaptive, output controller for globalcontrol of an aircraft or missile 570 that has been augmented with thehealth monitoring system shown in FIG. 14. This controller is identicalto that shown in FIG. 8 and operates in precisely the same manner exceptthat the adaption information 572 is made available to a global healthmonitoring system 574.

FIG. 19 is a flow diagram for a hierarchical control system with adistributed global controller 580 that has been augmented with thehealth monitoring system shown in FIG. 14. This controller is identicalto that shown in FIG. 9 and operates in precisely the same manner exceptthat the pre-processing information 582 is made available to a globalhealth monitoring system 584.

FIG. 20 is a flow diagram for a predictive adaptive, cascade controllerfor local control of an individual flow effector 590. The behavior ofthis control scheme is similar to that of the scheme depicted in FIG. 3with the difference lying in the manner in which the control input 592for the actuator is computed and the manner in which the control law isadapted 602. In the predictive adaptive scheme, the input/output 596,598 information is used to identify, either implicitly or explicitly,changes in the system model 600. The updated model 594 is used topredict the behavior 595 of the system at future times up to some fixedfuture time increment known as the control horizon (d). Based upon thechanges to the system model 600, the control law is adapted 602 and usedto generate a series of input commands 592 that will drive theidentified system to produce the desired output at the control horizon.The first of these input commands is used to drive the actuator 604.This is a digital control scheme and at each discrete time step, acomplete series of input commands that will produce the desired resultat the control horizon are generated though only the first of thesecommands is typically applied.

FIG. 21 is a flow diagram for a predictive adaptive, output feedbackcontroller for local control of an individual flow effector 610. Thebehavior of this control scheme is similar to that of the schemedepicted in FIG. 4. The difference between the system shown in FIG. 4and this system is that the adaption mechanism 612 and control lawcomputations 614 used are identical to that used in FIG. 20.

FIG. 22 is a flow diagram for a predictive adaptive, cascade controllerfor global control of an aircraft or missile 620. The behavior of thiscontrol scheme is similar to that of the scheme depicted in FIG. 7 savethat the predictive adaptive scheme shown in FIG. 20 is the adaptionmechanism 622.

FIG. 23 is a flow diagram for a predictive adaptive, output feedbackcontroller for global control of an aircraft or missile 630. Thebehavior of this control scheme is similar to that of the schemedepicted in FIG. 8 save that the predictive adaptive scheme shown inFIG. 20 is the adaption mechanism 632.

FIG. 24 is a flow diagram for a hierarchical control system with acentralized, cascade global controller with minor loop predictiveadaptive cascade feedback loops for local control of the individual floweffectors 640. The behavior of this control scheme is similar to that ofthe scheme depicted in FIG. 12 save that the predictive adaptive schemeshown in FIG. 20 is the adaption mechanism 642 in the local controlmodule.

FIG. 25 is a flow diagram for a hierarchical control system with acentralized, cascade global controller with minor loop predictiveadaptive output feedback loops for local control of the individual floweffectors 650. The behavior of this control scheme is similar to that ofthe scheme depicted in FIG. 13 save that the predictive adaptive schemeshown in FIG. 20 is the adaption mechanism 652 in the local controlmodule.

FIG. 26 is a flow diagram for a hierarchical control system with acentralized, cascade global controller with minor loop predictiveadaptive cascade feedback loops for local control of the individual floweffectors 660 that is augmented with the health monitoring system shownin FIG. 14. This controller is identical to that shown in FIG. 24 andoperates in precisely the same manner except that the adaptioninformation 662 is made available to a global health monitoring system664.

FIG. 27 is a flow diagram for a hierarchical control system with acentralized, cascade global controller with minor loop predictiveadaptive output feedback loops for local control of the individual floweffectors 670 that is augmented with the health monitoring system shownin FIG. 14. This controller is identical to that shown in FIG. 25 andoperates in precisely the same manner except that the adaptioninformation 672 is made available to a global health monitoring system674.

FIG. 28 is a flow diagram for a predictive adaptive, cascade controllerfor global control of an aircraft or missile 680 that is augmented withthe health monitoring system shown in FIG. 14. This controller isidentical to that shown in FIG. 20 and operates in precisely the samemanner except that the adaption information 682 is made available to aglobal health monitoring system 684.

FIG. 29 is a flow diagram for predictive adaptive, output feedbackcontroller for global control of an aircraft or missile 690 that isaugmented with the health monitoring system shown in FIG. 14. Thiscontroller is identical to that shown in FIG. 21 and operates inprecisely the same manner except that the adaption information 692 ismade available to a global health monitoring system 694.

FIG. 30 is a schematic view of one embodiment of a missile havingmultiple flow control zones, a number of the zones being onaerodynamically-coupled surfaces. In this specific embodiment, themissile 10 is shown having a forebody 18; an afterbody 13; a wing 11;and a fuselage 15 (which is the body of the aircraft or missile thatholds everything together), the fuselage containing or being coupledwith the parts of the forebody 18 and the afterbody 13. The afterbody 13comprises the part of the fuselage 15 and the tail section 17. The tailsection comprising tail fins 19. In various other embodiments, the tailsection 17 may include a rudder (not shown) and a boattail (not shown).The forebody 18 comprising a nose section 16. In this particularembodiment of the missile 10, there are a number of airflow controlzones 9. There are two airflow control zones 9 on the forebody 18, oneaerodynamic surface, (one in the nose section 16 and one immediately infront of the wing 11); one airflow control zone 9 on the wing 11; andone airflow control zone 9 on each of the three tail fins 19. The wing11 and the fuselage 15 an example of aerodynamically-coupled surfaces,each having at least one air flow control zone 9 in this embodiment.Each of the airflow control zones 9 comprise at least one active flowcontrol device or activatable flow effector 12, and in this particularembodiment each of the airflow control zones 9 comprise at least onesensor 14. For this embodiment, each of the airflow control zonescontain a number of active flow control device or activatable floweffectors 12 and sensors 14. The sensor having a signal and beingpositioned to detect forces or flow separation from that portion of theaerodynamic surface in the airflow control zone 9. The active flowcontrol device or activatable flow effectors 12 are controlled by one ormore logic devices (not shown). The logic devices have a control systemcomprising a separate local, closed loop control system for each flowcontrol zone 9, and a global control system to coordinate the localcontrol systems.

FIG. 31 is a schematic view of one embodiment of an aircraft havingmultiple flow control zones, a number of the airflow control zones beingon the same aerodynamic surface. The airplane can be any type ofaircraft, including commercial, military and space vehicles. Theaircraft 20 includes a tail 23, wings 24, forebody (nose) 18, afterbody13, and a fuselage 21 (which is the body of the aircraft that holdseverything together), the fuselage containing or being coupled with theparts of the forebody 18 and afterbody 13. The afterbody comprises partof the fuselage 21 behind the wings 24 and the tail 23. The forebody 18comprises that part of the fuselage 21 ahead of the wings 24 and anyother parts of the aircraft 20 in front of the wings 24. In thisspecific embodiment, there are six airflow control zones 9 on each ofthe wings 24. Each of the wings is a single aerodynamic surface. Each ofthe airflow control zones 9 in this embodiment each comprise at leastone active flow control device or activatable flow effector 12, and inthis specific embodiment 15 or more per each zone. In this embodiment,the sensors 14 are located across the center of the top surface of thewing 24. The sensors 14 having a signal and being positioned to detectforces or flow separation from that aerodynamic surface, and inparticular in the airflow control zone 9 in the sensors 14 vicinity. Theairflow control zones and/or flow effectors (including both active flowcontrol device or activatable flow effectors and traditional airflowcontrol surfaces) are controlled by one or more logic devices (notshown). The logic devices have a control system comprising a separatelocal, closed loop control system for each flow control zone 9, and aglobal control system to coordinate the local control systems.

FIG. 32 is a perspective view of a wing similar to the wing 24 of theaircraft 20 shown in FIG. 31. This wing section having active flowcontrol device or activatable flow effectors 12 and a sensor 14 mountedwithin a module 32 therein. The aircraft wing 24 can be designed withactive flow control device or activatable flow effectors 12 and sensors14 in a module 32 placed in the airflow control zones 9 to provide forbetter stability or maneuverability control with the present flowcontrol system. This flow control system is designed to provide for avariety of moments about the aircraft, which allow for both flowseparation and flow attachment and result in improved stability andmaneuverability. These moments can be used to change the drag, the yaw,the lift, the roll, the pitch and the thrust of the missile or aircraft.

FIG. 33 is a sectional view of section A-A′ of the aircraft wing asshown in FIG. 32. In this view, the cross-section of three modules areshown in two flow control zones 9, and the leading 33 and trailing edge34 of the wing 24. The cross-section of the modules 32 shows one of theactive flow control device or activatable flow effectors 12, in thiscase a deployable flow effector 12, and the sensor 14 for the module 32.Each of the modules are hardwired (although they could communicatethrough wireless components or other means) to one of two logic devices35. The first logic device 35 houses the local controller. The secondlogic device 36 houses the global controller.

FIG. 34A-B depict perspective views of one embodiment of a modulecontaining a co-located sensor, and 34A) an active flow control deviceor activatable flow effector (deployed) and 34B) an active flow controldevice or activatable flow effector (retracted). In this particularembodiment, the module 32 contains an active flow control device oractivatable flow effector 12 and a pressure sensor 14. The active flowcontrol device or activatable flow effector 12 being capable of beingdeployed into and retracted from, respectively, the fluid boundary layerflowing over the flow surface of the missile or aircraft forebodywherein the module 32 is employed. The deploying and retracting can beaccomplished using any device such as pneumatic pressure, hydraulicpressure, vacuum, a mechanical device such as a solenoid valve, amicroelectromechanical device, any combination thereof or the like. Themodule 32 mayor may not include a controller (not shown) internal to themodule. The pressure sensor 14 is connected to the controller (notshown). If the controller (not shown) is not internal to the module 32then the module 32 preferably further comprises a link between pressuresensor 14 and the controller, and another link between the controller(not shown) and deploying means (not shown). The controller in thisembodiment (not shown) is programmed to operate the deploying andretracting means in response to specific pressure conditions sensed atthe flow surface 16. The controller (not shown) can be any device suchas a computer, suitable for gathering information from the pressuresensors 14, and directing the activation of the active flow controldevice or activatable flow effectors 12. Where a number of active flowcontrol device or activatable flow effectors 12 and/or pressure sensors14 (or modules 32) are employed, the controller (or controllers) (notshown) can be programmed and connected to integrate each of the activeflow control device or activatable flow effectors 12, pressure sensors14 and modules 32 so that the output from all of the regions will becoordinated to enhance and possibly optimize the stabilization andmaneuverability of a missile or an aircraft forebody. Specific patternsof deployment and/or retraction of the flow effectors 12 can bedetermined to handle a variety of routine events and also incorporatedinto the control scheme.

FIG. 35 is a sectional, detailed view of a module 32 (as shown in FIG.34A-B) with an active flow control device or activatable flow effector(specifically a deployable flow effector) 12. In this specificembodiment, the flow effector 12 is movably attached to the upperportion 48 of the housing 46 of the module 32 and is attached to thelower portion 50 of the housing 46 of the module 32 by at least twofasteners 40. The upper portion 48 of the housing 46 mates with thelower portion 50 with a sealing ring (not shown) and a sealable,flexible element 44 there between. The flow effector 12 is deployed bypressure being applied to the flexible element 44. The flow effector 12has a biasing means (a spring) 42 which attaches at one end to the upperportion 48 of the housing 46 and at the other end to the base 54 of floweffector 12. Directly beneath the flow effector 12 is a valve 43, whichopens and closes to allow for the application of fluid or gas pressurefrom a pressure source not shown to be applied to the flexible element44 through a pneumatic pathway 52. A pressure sensor 14 senses fluidflow at or near the surface over which the fluid is flowing. Preferablythe pressure sensor at the surface of the airfoil, and most preferablyit is flush with such surface. The pressure sensor 14 can be anypressure sensor but advantageously is a micro electromechanical (MEMS)based or piezoelectric based sensor. MEMS devices are smallmechanical/electrical systems that perform small-scale tasks thatprovide large-scale effects. MEMS devices are generally manufacturedusing batch microfabrication technology, the same manufacturingtechnology used to make integrated circuits (IC's). Consequently, manyof the same benefits of IC manufacturing are applicable to MEMSmanufacturing including high reliability, high yield, and low cost.Furthermore, since ICs and MEMS are both silicon-based technologies andare fabricated using similar techniques, it is relatively easy to mergemicroelectronics and micromechanical elements onto the same substrates.Electrostatic actuated MEMS devices have two dominating advantages ascompared to other actuation mechanisms, which are high band width andlow power consumption. The sensor transmits a signal, in this case avoltage but it is understood to one skilled in the art that the signalcan be other than voltage, including, but not limited to, current,pressure, hydraulic or optical. The signal corresponds to the pressureit senses.

The pressure sensor 14 (or other sensors) are connected to a controller42 internal to the module 32 (or optionally external to the module). Thecontroller is a local controller 42 as described earlier. The controllerof the present invention is preferably a closed loop control system. Thecontroller can be used to create forces or reattach flow to theaerodynamic surface of the missile or aircraft through activation of theflow control devices (or effectors) 12. The pressure sensor transmits asignal to the controller 42 through the electrical connection 38 (inpractical application, multiple pressure sensors 14 send multiplesignals to the controller 42). The controller 42 processes the signalsto determine, through mathematical modeling, the dynamics of the flowsurface. Such dynamics include boundary layer separation and stall. Itis the predictive ability of the controller 42 in combination with theglobal controller (not shown), which provides for this function andexpands this system from being merely responsive. This is especiallyadvantageous for dynamic systems, which are nonlinear and time varyingand operating in challenging environments. The controller 42 produces anoutput signal to a monitor, recorder, alarm and/or any peripheral devicefor alarming, monitoring, or in some manner, affecting or precluding thedynamics upon its incipience. Advantageously, one of the components ofthe controller 42 is the ORICA™ controller, an extended horizon,adaptive, predictive controller, produced by Orbital Research, Inc. andpatented under U.S. Pat. No. 5,424,942, which is incorporated herein byreference. Under certain conditions, the controller 42 (or optionally anexternal controller) which is connected via electrical connection 46 tothe valve 43 causes the valve 43 to open thereby resulting in thedeployment of the flow effector(s) 12.

The multilevel, closed loop control system of the present invention notonly receives input in part from the sensors, but also can be set up toreceive input from a number of other sources. These sources can includebut are not limited to the autopilot, crash avoidance, or steeringsystems on an aircraft; or similar systems or non-integral, non-internalcommand control systems used to re-program a missile in flight. Themissile or aircraft can be maneuvered or stabilized using the flowcontrol system based in part on the sensors input and in part (ifnecessary) on new input from for example the autopilot into the closedloop control system to activate or deactivate the flow effectors asrequired.

Preferably, the pressure source (or other deployment and/or retractionmeans) is internal to the module 12. The sealable, flexible element 44referred to above can be made of an individual polymer or a combinationof polymers. The pressure source can be air bled from an aircraftturbine engine, a pressurized gas cartridge, or pressurized fluid. Thebiasing means is employed to urge the sealable, flexible element 44towards its quiescent state after pressure is removed or reduced. Thebiasing means can be any device or spring like means, such as vacuum orpressure, mechanical or electromechanical device.

The deployable portion of the active flow control device or activatableflow effectors shown in the previous Figures are small mechanical tabspreferably made from epoxy glass-fabric, and deactivate to assume aposition underneath the skin surface of the missile or aircraft in theirretracted state. Several examples of various embodiments of the floweffectors are shown in FIGS. 36A, 36B, 36C and 36D. Thesecross-sectional views demonstrate that rectangular 72, triangular 74,irregular 76, semi-circular 78, and square not shown can be used. Thepresent invention is, however, not limited to these shapes and it isenvisioned that any shape of flow effector known presently or conceivedof in the future by those skilled in the art may be used. Other types ofdeployable flow effectors which can be used these include but are notlimited to fences, bumps, dimples, and tubes. Upon controlledactivation, the flow effectors (deployable or other) manipulate theforebody of the missile or aircraft's vortical flow field to generatethe desired forces or flow separation. Single flow effectors orcombinations of flow effectors can be activated either statically orcycled at a varying frequency (oscillated) to obtain a desired sideforce or yawing moment. Varying frequency or oscillation of the floweffectors includes but is not limited to pulse width modulation or othertechniques known to those skilled in the art.

FIG. 37 is a sectional view of another embodiment of a deployable floweffector. The flow effectors 12 are further movably attached to acamshaft 94. The camshaft 94 moves in response to an electric motor 96to deploy and retract the flow effector 12. The motor is connected to acontroller 42. The controller 42 activates and deactivates thedeployable flow effector in response to at least in part the signal fromthe sensor 14.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the present inventionwithout departing from the spirit and scope of the invention. Thus, itis intended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed:
 1. A munition comprising: an aerodynamic surface orsurfaces, and a forebody and an afterbody; at least two air flow controlzones each comprising a discrete area or region and at least oneadjustable control surface on the aerodynamic surface or surfaces of themunition, at least one air flow control zone being on the forebody andat least one air flow control zone being on the afterbody, the at leastone adjustable control surface being activatable flow effectors adaptedto be activated, and controlled once activated; and one or more digitallogic devices, the one or more digital logic devices having a separatelocal, closed loop control system for adjusting the at least oneadjustable control surface in each flow control zone to, in part,maneuver the munition, and a global control system to coordinate thelocal, closed loop control systems.
 2. The munition in claim 1, whereinthe activatable flow effectors are one or more of wings, tailfins, orcanards.
 3. The munition in claim 2, further comprising at least onesensor or device having an electrical signal, wherein the first local,closed loop control system activates and controls the at least oneactivatable flow effector on each of the forebody and afterbody based onat least in part the signal of the at least one sensor or device.
 4. Themunition in claim 3, wherein the at least one flow effector on theforebody and the at least one flow effector on the afterbody are adaptedto be activated, controlled, and deactivated independently of each otherto minimize or create side forces on the munition forebody andafterbody.
 5. The munition in claim 4, further comprising a userinterface adapted to allow interaction between a human operator and themunition.
 6. The munition in claim 5, wherein the interface is adaptedfor the human operator to activate, control, and deactivate theactivatable flow effectors based at least in part on the signals fromthe at least one sensor or device.
 7. The munition in claim 2, whereinthe at least one activatable control surface being activatable floweffectors is/are deactivated when the activatable flow effector issubstantially flush with the aerodynamic surface or surfaces.
 8. Amunition comprising: an aerodynamic surface or surfaces, and a forebodyand an afterbody; at least two air flow control zones each comprising adiscrete area or region and at least one adjustable control surface onthe aerodynamic surface or surfaces of the munition, at least one airflow control zone being on the forebody and at least one air flowcontrol zone being on the afterbody, the at least one adjustable controlsurface being activatable flow effectors adapted to be activated, andcontrolled once activated; one or more digital logic devices, the one ormore digital logic devices having a separate local, closed loop controlsystem for adjusting the at least one adjustable control surface in eachflow control zone to, in part, maneuver the munition, and a globalcontrol system to coordinate the local, closed loop control systems; anda user interface adapted to allow interaction between a human operatorand the munition.
 9. The munition in claim 8, wherein the activatableflow effectors are one or more of wings, tailfins, or canards.
 10. Themunition in claim 9, further comprising at least one sensor or devicehaving an electrical signal, wherein the first local, closed loopcontrol system activates and controls the at least one activatable floweffector on each of the forebody and afterbody based on at least in partthe signal of the at least one sensor or device.
 11. The munition inclaim 10, wherein the at least one flow effector on the forebody and theat least one flow effector on the afterbody are adapted to be activated,controlled, and deactivated independently of each other to minimize orcreate side forces on the munition forebody and afterbody.
 12. Themunition in claim 11, wherein the interface is adapted for the humanoperator to activate, control, and deactivate the activatable floweffectors based at least in part on the signals from the at least onesensor or device.
 13. The munition in claim 12, wherein input from thehuman operator is adapted to control the global control system to inturn operate and control the local control systems to activate, control,or deactivate the activatable flow effectors.
 14. The munition in claim9, wherein the at least one activatable control surface beingactivatable flow effectors is/are deactivated when the activatable floweffector is substantially flush with the aerodynamic surface orsurfaces.
 15. A munition comprising: an aerodynamic surface or surfaces,and a forebody and an afterbody; at least two air flow control zoneseach comprising a discrete area or region and at least one adjustablecontrol surface on the aerodynamic surface or surfaces of the munition,at least one air flow control zone being on the forebody and at leastone air flow control zone being on the afterbody, the at least oneadjustable control surface being activatable flow effectors adapted tobe activated, and controlled once activated; one or more digital logicdevices, the one or more digital logic devices having a separate local,closed loop control system for adjusting the at least one adjustablecontrol surface in each flow control zone to, in part, maneuver themunition, and a global control system to coordinate the local, closedloop control systems; and at least one sensor or device having anelectrical signal, wherein the first local, closed loop control systemactivates and controls the at least one activatable flow effector oneach of the forebody and afterbody based on at least in part the signalof the at least one sensor or device.
 16. The munition in claim 15,wherein the activatable flow effectors are one or more of wings,tailfins, or canards.
 17. The munition in claim 16, wherein the at leastone flow effector on the forebody and the at least one flow effector onthe afterbody are adapted to be activated, controlled, and deactivatedindependently of each other to minimize or create side forces on themunition forebody and afterbody.
 18. The munition in claim 17, furthercomprising a user interface adapted to allow interaction between a humanoperator and the munition.
 19. The munition in claim 18, wherein theinterface is adapted for the human operator to activate, control, anddeactivate the activatable flow effectors based at least in part on thesignals from the at least one sensor or device.
 20. The munition inclaim 16, wherein the at least one activatable control surface beingactivatable flow effectors is/are deactivated when the activatable floweffector is substantially flush with the aerodynamic surface orsurfaces.